Calipers



R. JOHNSON.

CALIPERS.

APPLICATION, FILED FEB. 14, 1921.

1,410,189. Patentedmar. 21,1922.

lUNITEDv STATES PATENT OFFICE.`

ROBERT JOHNSON, OENEW BEDFORD, MASSACHUSETTS.

crimenes.

Toall 'whom t may concern: Y

Be it known that I, ROBERT JOHNSON, a citizenrof the United States,residing at New Bedford, in the county of Bristol and State ofMassachusetts, have invented certain new and useful Improvements inCalipers; and I do declarethe following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same. Y

. This invention relates to an improved pair of calipersy and one objectof the invention is to provide a pair of calipers having an improvedconstruction including a relatively stationary work-engaging arm, aguiding arm,and a relatively movable work-engag ing arm, the relativelymovable work-engagingarm'being provided with a gaging arm slidablyconnected with the guiding arm,

and the guiding arm being pivotally connectedwith the relativelystationary workengaging arm and the work-engaging arm and guiding armreleasably held in a set position.` Y

Another object of the invention is to pro* vide improved means forslidably connecting the gaging arm with the guiding arm so that thegaging arm may be readily moved but may be frictionally held in a setposition. Another object of the invention is to pro'- vide improvedmeans for pivotally mounting the relatively movable work-engaging armbetween the guiding arm and the vrelatively stationary work-engagingarm.

Another object of the invention is to so construct the calipersthat theparts thereof may be formed principally by casting from sheet metal thuspermitting the calipers to be Vcheaply produced.

`,This invention is illustrated in the accompanying drawings, wherein:

`Figure 1 is a top plan view of the improved calipers with the movablearm swung away from thestationary arm.

Figure 2 is a sectional view taken along vthe line 2-2 of Fig.1. l

Figure 3 is a sectional view taken along the line 3-3 of Fig. 1. 1

Figure 4 is a sectional view taken along the line 41 of Fig. 1.

Figure 5 is a sectional view 'taken along the line 5--5 of Fig. 1.

The improved calipers includes a relatively stationary worloengaging arm1,a relatively Patented Mar. 21, 1922.

implication med February 14, 1921. seriaim. 444,828.

movable work-engaging arm 2 and a guidmg arm 3. The guiding arm ispivotally connected with the relatively stationary work-engaging arm bymeans yof a bolt Il and this guiding arm is provided with an extendedend portion having a transversely extending slot 6 formed therein toreceivue a threadedv pin Y which is carried by the relatively stationarywork-engaging arm 1. A washer 8 is placed upon this `stem .or pin 7 andengaged by a securing nut 9 so that when the securingnut 9 is tightened,the washer will be brought into tight binding engagement withv theextended end portion 5 ofthe guiding arm and thus securely hold`the'guidmg arm and stationary work engaging arm in a set position. A.side arm extends from the guiding arm 3 and forms a bearing 10 withwhich the movable work engaging arm 2 is pivotally connected( by meansof a pivot bolt 11 which bolt will be loosened when it is desired toadjust the calipers and after the desired adjustment has been made thebolt may be tightened to securely but releasably hold the movablework-engaging arm in a set position. It should be noted that the bearing10 is placed in alinement with the longitudinal axis of the calipers sothat when the movable arm Iis swung upon its pivot, the gaging arm 12carried by the movable work-engaging. arm may move easily through thegroove or pocket 13 formed in the free end portion of the guiding arm 3.This gaging arm is arcuate and will have gage markings thereon, the gagemarkings being preferably in inches and fractions thereof which will beygraded according to the fineness of the work to be measured by means ofthe calipers.

The edge portion 13 of the guiding arm has been beveled as shown in Fig.1 sov that theV gage may be easily read, it being understood that thebeveled edge will move along the gaging arm 12 and correctly indicatethe l distance between the heads 14 of the two work-engaging arms 1 and2. With the bevele'cl edge 13 at the Zero mark of the gage, the heads14:.of the two arms are supposed to be in contact. If,'however, it isfound that the heads contact too soon or not soon enough, this can bereadily corrected by loosening the securing nut 9 and bringing the headstogether with the beveled edge 13 at the zero mark. The securing nut 9can then be tightened and the calipers `will be properly set for use. Inorder to permit the movable arm to be secured in a set position, therehas been providedwaVv clamp which is shown in detail in Figs, 4and `5.Referring to these figures, it Will be seen that the head Y 15 of theguiding arm has been provided With an opening and upon opposite sidesofithe opening 16, `iv'ith lopenings 17: The

clamp is provided With-abaselplatef18which: extends across the groove orseat 13 beneath provided at its ,outer end `with aj shieldV l19 whichengages theewunderface. of the head clamp ymay swing. A .threaded stein120 is Carried by y.this jbase i plate and extends Y through theopening. 1 6 and carries `a Washer `2,1 y, and secm-ringl nut 22 whichwill be tightened .when Iit desired .to ,have the movable arm w2 heldagainst movement. ]ins ,p23 I:are 'carried by `:this ,baseplate andslidably passed thiueh `the Geerlings V117 ,so that when the seeming mitstehtenecl, theibase plete will bepreventedliromturning.; It will ;th=usrbe Selen thatthe mut can bek tightened wftlwut any dangerofthe baseplate ofthe-clamp moving ,out of ,the proper V-position. AA,resilientwfriction ,strip 24 is `placed upon the upper face of thisbase Iplate '18 and-provided Vwith `openiiings to Vreceive the pins 23,

and with anuolpening between the ,openings iecegving ,the p1ns223 so@that the reduced .and lithiteaded,end` portionoi' :the stem 20V Vmay,beypassed through :the friction plate and screwed intothelthreadedaopening,2,5 formed in the basev plate of" ,the )ciampildlhen .this stem istightened, the vfriction `plate .Wi-ll ,bese'curelfyheld fin place as `shown in- IFig. l and l will extend ,beneath .and.fricltionally a engage .the under'face of 1#the gaging :arm `12. VWhen`the securing nut 22 is .tightlened, j,the friction plate Will jbebrOnght into `tight binding engagement with the :sage

arm. y n

YZV-hen the calipers are lin nee, gthey will be ,assembledas shown andafter the ,relatively stationary Work-engaging Aarm Ahas been ,properlyset `with respect to theguiding arm aspreviously 1 explained, thesecuring ynut Y9 Vwill bertightened. With the (threads, 14 `of theeverkensas'ne arm Contacting the beveled p Aedgefl will be positionedat' thezero mark .of ,the Mvgage Larm and as :the `:movable arm `issuuiflg avvay `from Athe stationary .farm and toward the guidingarma/the gaging `arm Vleasably held `zingfof the bolt 1lA orbytightening of ,the unut V92l so thatlthe ffriotion strip with the scale`markings:upon 'this ,gaging `arm indicating the amount the heads 14;have Y `fbeen",movedapart. Y IAfter thearmsf 1` and2 y.have :been `movedapart .the proper Vammnh `the `movable aimplmay be securely but-irefin,a set =positionfby 4tighteni 24 will very Ytightly engage the gagingarm instead of me, an arcuate leasing' 'ble Work-engaging arm simplyengaging the gaging arm a suicient amount to permit sliding of this armbut prevent accidental sliding movement of the arm.

I claim:

A pair of calipers comprising a guid- `ing arm having a transversely,extending pocket and a relatively stationary Work-engaging arm, a:relatively movable Work-engaging jaw pivotally mounted between theguiding arm andstationary arm, anarcuate gaging arm extending from said,jaw through the pocket )in .said guiding anni,

and elainpingmeans carried `by said guiding arm and yincluding aresilient stripen'gag` ing said gagingarm `to Arictionally `held sameagainst sliding movement.

2.1 'Ehe Structure 'oflclam lha-ving the ,clamp in the form` of a 4rigidA:base :havlnga fulcnum at one end engaging the underfaoe of the guidingarm and extending lacrosS-the Apocket formed -;therein, alfresilientplate between the base andrgudingarlm .and engaging the gaging arm, athreaded stem extending from" the `base,through the resilient plate -andguiding arm, .aseeur- .ing nut narredby said stem .and VAengaeillg .the.up-per ,face of said guidingarm, and

means lfor holding the ,baseandplatefagainst turning when yfsaid nut istightened 3, A pair :Ofl'calpers comprising@ rela- Aarm l and ,having Aafpocket, one rof said arms being extended beyond its Ypivot point ,andprovided `with altransverse ,.slot, a pin Y carried by the ysecond armandlextendng .through lthe slot and carrying :means for en-v;.gagingfthe Vexteirlded-,end portion of the -rst `arm to releasablyhold the arms against movement, a `bearing `extendir1gy LIQII thepivoted end of the guiding arm and extend- V:ing between said arms,a`relatively movable Work-engaging arm npivoted to saidlgbea-r- :arm'extending from the free end portion of .the movaalld extldng tivelystationary Work-engaging atm, la l guiding .arm hating a pocket adjacentits ree a end and hav-lng a .slde extension eformf Y ill 0 through thepocket in the guidingarm, and f 4clamp means .carriedfgby the `guidingarm andincluding aljresilientstrip; engaging sald gaging arm tofrietionally hold the same against movement in the pocket.

5. A pair of calipers comprising a guiding arm having a pocket, astationary workengaging arm, a movable work-engaging arm pivotallymounted between the stationary arm and guiding arm, a gauge arm eX-tending from said movable arm through the pocket of said guiding arm,and means in said pocket for rietionally engaging said gauge arm andreleasably holding the movable arm in a set position.

6. A paii` of calipers comprising a stationary work-engaging arm, aguiding arm, a movable work-engaging arm pivotally mounted between thestationary arm and the guiding arm, a gauging arm carried by saidmovable arm and extending across said guiding arm7 and resilient meansengaging said gauging-arm and friotionally holding said movable arm in aset position.

In testimony whereof I have hereunto set my hand.

ROBERT JOHNSON.

